When you say the words “But it’s only Peterborough...” to Cardiff City striker Heidar Helguson it is hard to describe the look on the striker’s face.

Of Viking stock and proving a warrior indeed for the Bluebirds this campaign, that craggy visage, which already appears carved from the volcanic rock which litters his Icelandic homeland, starts to look even more fearsome.

Red hot lava doesn’t literally come pouring out of his ears, but, well, you get the picture.

Let’s put it this way, you wish you hadn’t mentioned it.

But with rock-bottom Posh arriving at the Cardiff City Stadium on Saturday to face the Championship-topping Bluebirds, for a division that really does not do foregone conclusions, this encounter is surely as close as one gets.

Darren Ferguson’s men are seemingly poised to be cut adrift from the Championship, five points from safety and currently languishing in a pitiful run of form that sees them without a win in eight games, seven of those defeats.

They have shipped seven goals in their last two games, although they did make high-flying Middlesbrough earn their corn at London Road on Saturday before finally succumbing 3-2.

Malky Mackay’s men, conversely, are in absolutely scintillating form and sit three points clear at the top of the table thanks to a 16-point haul from the last 18 on offer.

And in the Welsh capital itself Helguson and his team-mates sit imperious, it’s as their manager put it so eloquently: “Ten have come and 10 have gone – and not one point has crossed the Severn Bridge.”

It’s record-breaking stuff – the Bluebirds had never won 10 at home on the bounce in the league before and surely it will be 11 by Saturday evening.

After all, it’s only...

“To say ‘oh it is only Peterborough’ is disrespectful, I think,” Helguson mutters through narrowed eyes.

“Any complacency has to be avoided absolutely. Peterborough have earned the right to play in the Championship.

“And we see on many occasions, week-in and week-out, where teams that before the game were the underdogs have gone and beaten the opposition.”

The frontman is, of course, correct with, as the old saying goes, the second-tier is only predictable for its unpredictability.

Note Boro a few weeks back humbled at home by Bristol City or, more recently, fellow Bluebirds’ pursuers Leicester relieved in the end on Saturday to grab a late equaliser for a 2-2 draw with out-of-sorts Barnsley.

Indeed you need only to cast your gaze as far back as City’s last home outing – against former manager Dave Jones’ Sheffield Wednesday – when the relegation-threatened Owls hung on with dogged determination and came close to spoiling the Bluebirds’ record-breaking exploits to recognise the perils of the division.

Under Mackay, however, the Bluebirds are a bit like that this season, able to dig out a result where in the past they might not have managed to do so.

Helguson, too, is becoming a symbol of such defiance with the Icelander’s brand of steely determination starting to mirror the relentless pursuit of promotion at Cardiff.

He is also starting to establish himself as a bit of a fans’ favourite too, City supporters always taking a fighter to their hearts even if it comes at the expense of finesse.

Those prepared to roll their sleeves up and get stuck in have been lauded by the faithful and Helguson’s take no prisoners attitude ticks all the boxes.

Fans’ forums throb with admiration, his eight goals have helped, and the fact he set up three of the four goals at Blackburn on Friday have also done him no harm.

But it would be fair to say Helguson had to win a few people over when he arrived from Queens Park Rangers in the summer.

He may have played a big part in getting Rangers to the Premier League in 2011 and then gone on to become their top scorer in the top flight in the following campaign, but at the age of 35 many wondered if he had what it took to lead the line right through a brutal Championship season.

But Mackay did not expect to make such demands of his frontman until fellow summer arrival Nicky Maynard suffered serious knee ligament at Millwall in September, the former West Ham man ruled out for the rest of the season.

It is a responsibility he admits he is enjoying, and particularly being part of that record-busting home form.

“We enjoy playing in front of our own fans a lot,” he said.

“It is a fortress for us and I can’t see anyone really wanting to come and play us there.

“But we must perform there.

“Whether it’s away from home or at the Cardiff City Stadium it does not matter.

“The fact we have won 10 on the spin does not really matter at all against Peterborough.

“It’s a new game and we are going to have to be on top of things again to beat them.

“People say it all the time and it is true, there are no easy games in the Championship, absolutely none at all.